Carburetor



Aug. 16, 1932.

H, H. c. WEED CARBURETOR Filed June 14. 1930 2 Sheets-Sheet 2 ENVENTCRum. W5 5 a m ATTORNEY nuen'n. 'c.

OF GLA'QTON, MISSOURI, ASSIGNOK TO CARTER CABBUBETOBCOB- Patented Aug.16, 1932 ESfPATE r OFFICE.

v rom'rIoR, or s'r aoum, ,mssouannconroaanon or DELAWARE cannumironApplication am June 14,

internal vcombustion engines, and particubut also, generally,

, a carburetor in which the boiling of gine. I

Other objects will appearfrom the follow-Q larly to carburetors of thedowndraft type,

are exposed to heat from the engine.

It is an object of this invention to provide the fuel will be prevented.

- his a further object of this invention to provide a carburetor inwhich the fuel is sub jected to a cooling action. a p

It is a further object of this invention to provide a carburetor inwhich the fuel is pro- J from the heat of the em tected or insulated mgdescription and the accompanying claims.

The invention will-be upon consideration of .the accompanying drawings,referring to which: I

Figure lrepresents a sectional elevation of a downdraft carburetorconstructed ac cording to my invention.

Figure 2 represents a plan view of the car-. buretor shown in Figure 1.

Figure 3 is'a sectional plan view of the carburetor taken along the line3-3 of Figurel.

The carburetor comprises a main body member 1, having a verticallyextending air chamber 2 at the upper end thereof. This )assa ewa iscontracted into a venturi, the

throat of which is indicated at 3, and the a venturi tapers graduallydownwardly and outwardly, the cylindrical outlet passageway 5. Thisoutlet is surrounded by a flange 6 which is provided with bolt holes 7or any suitable means by which it may be attached to the manifold of aninternal combustion engine.

A butterfly throttle 8 mounted in a conventional manner upon a shaft 9is provided. The up is expa ded to a size sufficient to receive the fuelbowl 11 which is attached to a support;

member '12. The upper rim of the bowl is held in fluid tight relation tothe support' member at 13, a suitable gasket being pro to anycarburetors which better understood as indicated at 4, terminating in erpart of the body of the carburetor 1930. Serial No. 461,089.

buretor and retained in position by bolts 14,

as shown in Figure 2, or other suitable means. The support member isprovided with an extension 15 extending downwardly into the bowl 11and'this extension isthreaded at 16 "to receive the end of a flangednozzle memher or inverted standpipe 17which, when screwed into thethreads 16,'retains' the fuel bowl tightly in place. The standpipe isprovided with a 'restrictedportion or primary venturi 18 which tapersgradually "out to the cylindrical bore 19 of the standpi'pe.

The extension 15 of the support member is provided with a well ordownwardly extending opening 20 which is in communication with theatmosphere at its upper end. In the lower portion'of this well a'concentric member 21 is fitted, and this member carries an acceleratingwell 22 and an inverted thimble 23 having one ormore accelerating holes24 formed therein. The member 21 isprovided witha bore 25 to looselyreceive a "nozzle member 26. This nozzle member -extends upwardly to apoint just above the float level in the bowl and below the top of thethimble, as shown, and it extends downwardly to a point near the throatof the venturi 18. It will be understood that the nozzle member isattached to the support member 12 bythreads 27 or other suitable means.g

A spider or cross member 28 is formed in the member 12 to extend acrossthe lower part ofthe well 20 to receive the threads 25'and 27. A bore29is formedextendin'g transversely into the extension 15 andlongitudinally through thespider 28. This bore is threaded as shown toreceive a jet nozzle 30 which controls the main fuel entrance to thecarburetor. It will be understood that the bore 29 communicates with thebore 25 and through the accelerating holes 24 with the well22.

Fuel is supplied to the fuel bowl 11 from a conventional fuel pump (notshown), or other suitable means. A pipeconnection 31 receives the fuelwhich is supplied to the carburetor in a conventional mannerf Thecarburetor is-provided with a fuel pump 32 opon the shaft 35 isprovided. An idle tube connects with the passage 29 and also with theport 37 through the passages 38,- 39, 40,

' and 41. Air bleeds 50 and 51 are provided to prevent siphoning whenthe device is not in operation.

The carburetor is shown as being mounted on a manifold 10 of an internalcombustion engine. This manifold is provided, in a conventional manner,with heating means, such as an exhaust conduit 42 through which passesat least a portion of the exhaust from the engine for the purpose ofmore completely vaporizing the mixture as it passes to theen ine.

t will be understood that this manifold gets extremely hot, particularlyafter a period of high speed operation. \Vhen the motor is slowed down,after being operated at a high speed, the rate of air and fuel flowthrough the carburetor and manifold decreases, and the heat of theengine readily communicates to the carburetor.. important object of thisinvention to restrict the communication of heat to the fuel in the bowl,and the substantial annular space 43 between the fuel bowl and the outerwall of the carburetor is provided for that purpose. During theoperation of the engine, air is drawn downwardly through this annularportion and thereby traversesthe walls of the fuel bowl 11. The highspeed of this air substantially prevents transference of heat from thebody portion 1 in the carburetor to the bowl, and even when the engineslows down or stops, a thick layer of air between the carburetor bodyand the bowl forms a substantial resistance to the transference of heat.

The operation of the device is as follows:

Fuel is supplied from a conventional fuel pump vacuum tank or othersupply device to the inlet 31 and passes through the conventional floatvalve (not shown) which is controlled by the float 44 which maintains afuel level slightly below the u per end of the tube 26. Suctionoccurring, ue to the operation of the engine, draws air down through theprimary air inlet 45-past the spider 28 and through the venturi 18,thereby creating a suction in the interior of the thimble 23 and drawingfuel through the jet 30 and up over the ,top of the, tube 26. Air alsoenters the accelerating holes 24 and mingles with the fuel inside thethimble, the air and fuel then passing in the form of an emulsion downthrough the conduit 26.

The major portion of the air entering the carburetor flows through theannular space 43 around the bowl. and begins to mix with the primary airand fuel at the throat of the venturi 3.

It will be understood that the particular It is an construction of theinterior of the carburetor bowl and the fuel mixing passages may bevaried without affecting the utility of my invention. In the presentcase, the carburetor and the fuel bowl are cooled by air passing throughthe bowl and also by a larger quantity of air assing around the bowl,but it should be un erstood that my invention is not limited to acarburetor in which air passes through the bowl, and that it is sus:ceptible of application to .carburetors in which none of the air entersthe fuel bowl.

I claim:

1. In a carburetor, means forming a mixing chamber, a throttle valvecontrolling the flow through said mixin chamber, a venturi discharginginto sai mixing chamber, a frusto conical air inlet'chamber having itssmall end dischargin into said venturi, a fuel bowl substantial y withinsaid air chamber and slightly spaced therefrom, thereby forming an airpassage between said fuel bowl and said frusto conical chamber.

2. In a downdraft carburetor, a fuel bowl,

co-axially mounted a passage through said fuel bowl, an air inair hornsurrounding said fuel bowl and .o

spaced therefrom to rm a substantial annular downwardly conducting airpassage around said fuel bowl, said air horn being constricted belowsaid fuel bowl to form a venturi, and a throttle valve mounted belowsaid venturi for controlling the flow of carbureted fluid through thecarburetor.

In testimony whereof, I aflix my signature. HUGH H. C. WEED.

IllO

